The Final Word
The Frontier's 4.0L V-6 is rated at the crankshaft with 261 hp and 285 lb-ft of torque. Our truck put 221 hp and 238 lb-ft of torque to the rear wheels in stock form, as measured by a Dyno Dynamics Dynamometer. That's a 16-percent loss through the drivetrain. Still, our truck routinely averaged between 19 and 21.2 mpg on the highway. The addition of the Cat4ward headers added 9 hp and 6 lb-ft of torque, and we saw a 3-mpg improvement in fuel economy. The horsepower peaked at 5,900 rpm, while the torque fell off at 4,150 rpm.

On the highway, Zippy was still zippy but with a slight growl through the new tubes. The power improvement wasn't noticeable from the seat of our pants, but the increase in fuel economy is substantial.

JBA Headers
7149 Mission Gorge Rd.Suite D
San Diego
CA  92120